Fatto matematico: 2273 is the number of functional graphs on 10 vertices.
Trivia: 2273 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: March 22nd is the day in 1997 that Tara Lipinski, age 14 years and 10 months, becomes the youngest champion women's World Figure Skating Champion.